Ulead GIF animator software error message

Please solve my problem. Today Ulead GIF Animator software doesn’t allow me to edit a .avi file in it. I never faced this problem before. what should I do to edit that avi file in ulead Gif animator?

unable to read the video file. 'C:Documents and settingsusermy documents Any video converterAVI You know what OI' Jack Burton always Says.. _xvid.avi'
